Method for the crosswise shrinking of a cylindrical part in a tubular part, tool kit for its implementation, and assembly of two corresponding parts

Abstract

An assembly ( 10 ) formed of two parts pressed together in cruciform arrangement comprises a cylindrical part ( 11 ) and a tubular part ( 12 ). The tubular part ( 12 ) has a transverse hole ( 14 ) bordered by rims ( 18 ) extending toward each other. A spacer ( 16 ) in the form of a ring is inserted between the walls ( 15 ) of the tubular part ( 12 ), surrounding the region where the hole is to be formed. The rims are then deflected toward each other into engagement with the interior of the ring, the ring having a height equal to the distance between the walls ( 15 ). Thus, the ring ( 16 ) braces the tubular part ( 12 ) internally around the hole ( 14 ).

What is claimed is:  
     
       1. A tool for pressing a cylindrical part into a tubular part through a hole passing completely through opposite walls of the tubular part, which comprises a first stepped punch adapted to punch a preliminary hole, said first punch having a first section having a free end adapted to punch a preliminary hole in said tube and a second section with a progressive transverse profile adapted to perform coarse pressing and a third section adapted to perform finish pressing, the tool having a second stepped punch adapted to perform successive pressing and sizing, the second stepped punch having a frustoconical first section a cylindrical second section and, alternating with connecting sections of lesser diameter, at least one other cylindrical section having a diameter greater than the diameter of the second cylindrical section for sizing the hole obtained in a plurality of passes. 
     
     
       2. A tool as claimed in claim  1 , having a free end which is circumferentially divided into at least two lips. 
     
     
       3. A tool as claimed in claim  2 , wherein edges of said two lips are continuously joined together to form a cutting edge. 
     
     
       4. A cruciform assembly of a cylindrical part and a tubular part produced by the method of inserting a ring ( 16 ) into the tubular part, forming rims ( 18 ) extending toward each other from the material of opposite walls about a hole and within said ring, the ring having a height substantially equal to the distance between said opposite walls adjacent said hole, and pressing said cylindrical part through said hole. 
     
     
       5. An assembly as claimed in claim  4 , wherein said rims extend about the entire periphery of the hole. 
     
     
       6. An assembly as claimed in claim  4 , wherein each rim has a substantially constant height all around the hole. 
     
     
       7. An assembly as claimed in claim  4 , wherein each rim is pressed against an inside surface of the ring. 
     
     
       8. An assembly as claimed in claim  4 , wherein said rims have free edges spaced from each other in a direction parallel to the cylindrical part. 
     
     
       9. An assembly as claimed in claim  4 , wherein the ring is a closed ring.